# -*- coding:utf-8 -*-
#Author LJ 
#Mail:admin@attacker.club
#Site:blog.attacker.club
#description
letters = ['a','b','z','d']
print "原来元素",letters
letters.sort()
print "排序",letters
letters.reverse()
print "反向排序",letters
print letters
newletters = sorted(letters)
print "排序副本",newletters #原列表的有序副本，不影响原列表